Question

An Sulfur tetrafluoride gas is collected at 23.0 °C in an evacuated flask with a measured volume of 20.0 L. When all the gas has been collected, the pressure in the flask is measured to be 0.230 atm . Calculate the mass and number of moles of sulfur tetrafluoride gas that were collected. Be sure your answer has the correct number of significant digits. mass: 1 g N10 mole: mol X & ? Explanation Check​

Answer 1

mass = 20.48 g

moles=0.1895

Further explanation

In general, the gas equation can be written  

Pv=nRT  

where  

P = pressure, atm  

V = volume, liter  

n = number of moles  

R = gas constant = 0.08205 L.atm / mol K  

T = temperature, Kelvin  

P=0.23 atm

V=20 L

T=23+273=296 K

$\tt n=\dfrac{PV}{RT}=\dfrac{0.23\times 20}{0.082\times 296}=0.1895$

mass SF₄ (MW=108,07 g/mol) :

$\tt 0.1895\times 108,07 g/mol=20.48~g$